Front panel for automatic industrial process controller - uses gas discharge display bars for system variables and capacitive touch sensitive switches for operator control

摘要

The system may be manually or automatically operated to compare an operating variable (A) with a set value (B) and produce an error signal (C). The error signal is applied to a controller which alters the operating variable. The controller has a front panel (10) which has three gas discharge type display scales: one for the set value, one for the measured value, and one for the error value. Each scale is formed of an array of electrodes along the length of the scale to give progressive illumination as the value to be displayed increases. The controller front panel has also provision for capacitance type touch sensitive controls to provide access to process by the operator.